Master Promethazine (Phenergan) with Picmonic for Nursing RN

With Picmonic, facts become pictures. We've taken what the science shows - image mnemonics work - but we've boosted the effectiveness by building and associating memorable characters, interesting audio stories, and built-in quizzing.

Promethazine (Phenergan)

Promethazine (Phenergan) is an H1 receptor antagonist, and a weak dopamine antagonist that competes with histamine-1 and dopamine-2 receptors in the chemoreceptor trigger zone of the brain to decrease nausea, vomiting, and motion sickness. Side effects include respiratory depression, sedation, dry mouth, urinary retention, and extrapyramidal symptoms, such as dystonia, akathisia, and parkinsonism. This medication should not be given to children under the age of two, due to increased risk of death, related to severe respiratory depression. Keep in mind, if promethazine must be given intravenously, it should be administered through a large bore IV with a flow rate to prevent tissue necrosis. Extravasation can lead to serious complications, such as abscess formation and gangrene that requires amputation.
Histamine H1 Receptor Antagonist
History-man with (1) Wand in Ant-toga

Promethazine competes with histamine at histamine-1 receptor sites throughout the body. The medication’s antiemetic property is likely related to its effect in the chemoreceptor trigger zone of the brain.

Weak Dopamine Antagonist
Weak Doberman in Ant-toga

Promethazine also functions as a weak dopamine antagonist, blocking dopamine-2 receptors in the chemoreceptor trigger zone, thus decreasing nausea and vomiting.

Nausea and Vomiting

This medication is indicated in the treatment of nausea and vomiting related to chemotherapy and surgical procedures.

Motion Sickness

Promethazine may also be prescribed to treat motion sickness.

Respiratory Depression
Deflated Lungs

This medication can cause severe respiratory depression and should not be used in children under the age of two.


Sedation, CNS depression, and fatigue are side effects associated with promethazine. Patients should be advised to avoid hazardous activities, such as driving while taking this medication.

Anticholinergic Effects

Patients may also experience anticholinergic effects, such as dry mouth and urinary retention. The patient should be encouraged to void before taking this medication.

Extrapyramidal Symptoms

Movement disorders or extrapyramidal effects can be induced by promethazine. Patients may develop muscle spasms or contractions, restlessness, bradykinesia, and tremor.

Use Large Bore IV
Large Bore IV

If extravasation occurs during intravenous administration, promethazine can cause tissue death and abscess formation. To ensure patient safety, this medication should be administered through a large bore IV, at a rate of no more than 25 mg/min. Patients should be encouraged to report pain or burning during IV administration.

Monitor for Tissue Necrosis
Monitor Tissue-box Necrosis-crow

When given via IV push, patients receiving promethazine should be closely monitored for signs of tissue necrosis.

Unlock all 10 facts & definitions with Picmonic Free!

Take the Promethazine (Phenergan) Quiz

Picmonic's rapid review multiple-choice quiz allows you to assess your knowledge.

It's worth every penny

Our Story Mnemonics Increase Mastery and Retention

Memorize facts with phonetic mnemonics

Unforgettable characters with concise but impactful videos (2-4 min each)

Ace Your Registered Nurse (RN) Classes & Exams with Picmonic:

Over 1,200,000 students use Picmonic’s picture mnemonics to improve knowledge, retention, and exam performance.

Choose the #1 Registered Nurse (RN) student study app.

Picmonic for Registered Nurse (RN) covers information that is relevant to your entire Registered Nurse (RN) education. Whether you’re studying for your classes or getting ready to conquer your NCLEX®-RN, Hesi, ATI, TEAS test, Kaplan exams, we’re here to help.

Works better than traditional Registered Nurse (RN) flashcards.

Research shows that students who use Picmonic see a 331% improvement in memory retention and a 50% improvement in test scores.